Looking to get a cheap server for my needs

I was looking around and saw that getting an older server wasn't too expensive. I need a nas so I was thinking something with freenas or linux and btrfs with owncloud and syncthing. I was also thinking of doing several virtual machines to do some web development and running something like sirius personal assistant. I would also like to have 2 gigabit ethernet ports so I can forward my internet connection to my PC. I would really love to get some hands on experience on enterprise hardware as I know very little on it.
I'm not too sure how much power I would need and was thinking of having 2 1 Tb sata drives for now and possibly having a 300Gb 15k drive for VMs. I am currently a student and would like to have an option that is around $400 (Without Drives). Also, how would I go about forwarding my ethernet port to my PC? Is there anything special I have to do to connect normal sata drives? Would this kind of workload benefit from having a lot of cpu cores or ram?
Any advice is appreciated, I'm looking for help on the hardware as well as the setup. Was looking here:

I'm currently a university student and I am tight on budget.

Hi, I'm also on the fence if I should buy an old Server/Workstation for nearly the same reasons like you. I have some concerns about old xeon's and gpu pass through to my vm's ... with your budged you should get some amd fx stuff too ... some mobos should support ecc if redundancy is a concern for you.

Currently I have a GA-990FXA-UD3 and FX 8320e @4.4 with 16gb fast non ecc ram ... with 2-3 vm's running in vbox I never have an issue on ubunut 15.04 with a moderate small business workload.

You also can throw some nic's on the pci-e and a ssd for speed.

If you need really more power take the advice form @moneylotion

Ha, I think I bought a pair of those r900 once, thinking my dreams were met. Only to subsequently discover they are like 220v, or use a ton of power, and not at all practical for my single user can throw at it. I was lucky the seller on eBay was kind in canceling my order. But those cores are lusty.

I would say, it sounds like you would benefit first from focusing on a NAS. If you build it right, with about two good cores or so, you can pretty much do any NAS type things. Even great for a basic development environment, if you take it easy and don't go nuts with debugging weird dependencies that cause major downtime... You should have more RAM than you need, which is really the factor, since you're not going to eat it up with 20 website tabs.

I built a mini itx NAS with Mini ITX. In highinsight, the form factor is great aesthetically for a home or small space, but I would have liked more drives per dollar. I also think towers cases are aesthetically harder to decorate or design in a room... I like shorter or wider cases. They feel more minimal.

Mini itx boards and cases are generally not designed with extreme expansion in mind, so you're sort of just creating a a purpose built piece of hardware, with no major upgrades in the future, other than maybe processor. I ended up building two of the exact same systems about 8 months apart, and gearing up for what I should do next. This isn't a bad thing, they are quiet, and small. But maybe I could save money building something bigger ?

I think a 5 drive raid is far better than 4 though. And if I had 6 drives, I would likely feel out two drive parity, though I don't know if ZFS has much more overhead (for a 2 core processor).

Here are the complete specs of my builds (actually have two identical NASs in this form factor) —
MB - Gigabyte GA-H97N-WIFI
Case - Fractal Design Node 304
Processor - intel g3258
RAM - 16 gb, non ecc
OS / RAID - Ubuntu 14.04 + ZFS
PSU - Corsair hm850 — had it used from an old project, could save a lot of money going with something around 500W gold

I think my motherboard is also overkill. I will buy it again, because I like options, but I don't need wireless AC, or dual HDMI. Lots of people really push the benefit of ECC, and not doubting that it is effective against corruption. But ZFS has checksum, so hopefully I will get through. Needless to say, the money I saved I bought more hard drives anyway.

The drives, I don't really think you need to worry about NAS quality drives, especially if you have a big enough raid. Just keep an eye on the NAS, and use it so you can notice or CHECK if there are any raid issues.

And definitely remember that RAID is not backup.

I went with these toshiba drives

No complaints. They're fast, pretty cool temperature, and I think they have a decent warranty.
Considering everything is going through gigabit, I could probably use sata2.

If you NEED a VM cluster, for development, or lab stuff -
I would start with something i7, or as many cores as you can, and as much RAM as it can take.
You're going to basically be bound to gigabit, so that's probably the biggest limitation, depending on what you're trying to do.

Realistically if you're developing web, you don't need these many services on locally to support huge enterprise infrastructure.. So you can spin up your development VM when your at the desk, and tear them down, or grab them off your NAS when you're ready to work.

Using VMs to contain web projects is what I do as well, but I also basically use like one VPS or maybe one client STAGING VPS. This will rarely run anything more than web server and maybe a email server. Everything else I keep locally on my NAS, or spin up as needed on my desktop (i7).

Trust me I want more cores, or power as well, but I can't at this point utilize more cores, unless I just a couple of huge things on until they hang, etc. In terms of web development, if your server is built well, you can serve literally thousands of users on two cores, and 4 or 8 gb of ram. And if you're talking about scaling to multiple sites, load balancing, or some sort of cluster, that's sort of a different discussion, which I am happy to maybe talk about but on another thread or PM.

@Seth @Eduardo_Salas
long post before -
something to consider, which I have done -
external drives are a good way to get going. Even two solo drives, doesn't need to be raid. Just something so you can manually manage between the two. Maybe you can find an old computer, or use your current rig to provide NAS sharing. I did this for years with roommates, before I built my NAS.

Two drives was really when I felt serious benefits for file management. And could have redundancy.
Keep in mind, Google's policy on redundancy is 3-2-1
Three copies, two location, equals one backup.
Even if you have two drives, you still might want to back things up more seriously...

I can't completely vouch for anyone on eBay, but I have had luck buying "a lot" of drives on eBay. I bought 10 3tb green drives for ~$400 - which were referbs - they arrived in great condition with no visible wear in sealed bags.
Not sure how I feel about full time NAS use, I bought them for a cold storage NAS that i'm piecing out of EBAY parts... Anyway, I've been giving the drives out to clients and friends, so who knows. I think I'm down to like 7... They seems great! It seriously is something I would consider for a lot of people, not just a low budget. It's kind of serious power move, to rotate between multiple drives. I know my college rotates drives to like carbonate, or a vault somewhere to backup our grades. They use a pelican case, so maybe you should use like tupperwear if it's really important. And I miss floppies, but this is more fun.

After thinking about this quite a bit what i ended up doing is grabbing a VPS which I pay monthly for to do some web development. My storage solution at the moment isn't the cleanest but I don't want to lose my data (I have already lost some code from HDD dying), I have two extra hdds on my system, one for Storage and the other for redundancy and I'm using Amazon Cloud Drive to save backups to. I will probably go a while more like this and upgrade my PC and get a NAS later down the line after I save up a bit. I'll probably drop some money for 3 2TB drives, 2 active and 1 spare.